Historical development

The field of international relations emerged at the beginning of the 20th century largely in the West and in particular in the United States as that country grew in power and influence. Whereas the study of international relations in the newly founded Soviet Union and later in communist China was stultified by officially imposed Marxist ideology, in the West the field flourished as the result of a number of factors: a growing demand to find less-dangerous and more-effective means of conducting relations between peoples, societies, governments, and economies; a surge of writing and research inspired by the belief that systematic observation and inquiry could dispel ignorance and serve human betterment; and the popularization of political affairs, including foreign affairs. The traditional view that foreign and military matters should remain the exclusive preserve of rulers and other elites yielded to the belief that such matters constituted an important concern and responsibility of all citizens. This increasing popularization of international relations reinforced the idea that general education should include instruction in foreign affairs and that knowledge should be advanced in the interests of greater public control and oversight of foreign and military policy.

This new perspective was articulated by U.S. President Woodrow Wilson (1913–21) in his program for relations between the Great Powers following a settlement of World War I. The first of his Fourteen Points, as his program came to be known, was a call for “open covenants of peace, openly arrived at” in place of the secret treaties that were believed to have contributed to the outbreak of the war. The extreme devastation caused by the war strengthened the conviction among political leaders that not enough was known about international relations and that universities should promote research and teaching on issues related to international cooperation and war and peace.

International relations scholarship prior to World War I was conducted primarily in two loosely organized branches of learning: diplomatic history and international law. Involving meticulous archival and other primary-source research, diplomatic history emphasized the uniqueness of international events and the methods of diplomacy as it was actually conducted. International law—especially the law of war—had a long history in international relations and was viewed as the source of fundamental normative standards of international conduct. The emergence of international relations was to broaden the scope of international law beyond this traditional focal point.

Between the two world wars

During the 1920s new centres, institutes, schools, and university departments devoted to teaching and research in international relations were created in Europe and North America. In addition, private organizations promoting the study of international relations were formed, and substantial philanthropic grants were made to support scholarly journals, to sponsor training institutes, conferences, and seminars, and to stimulate university research.

Three subject areas initially commanded the most attention, each having its roots in World War I. During the revolutionary upheavals at the end of the war, major portions of the government archives of imperial Russia and imperial Germany were opened, making possible some impressive scholarly work in diplomatic history that pieced together the unknown history of prewar alliances, secret diplomacy, and military planning. These materials were integrated to provide detailed explanations of the origins of World War I. Among such works several are particularly noteworthy, including Sidney Bradshaw Fay’s meticulous The Origins of the World War (1928), which explored prewar diplomacy and alliance systems; Bernadotte E. Schmitt’s The Coming of the War, 1914 (1930) and Triple Alliance and Triple Entente (1934); Pierre Renouvin’s The Immediate Origins of the War (1928); Winston Churchill’s The World Crisis (1923–29); and Arnold J. Toynbee’s The World After the Peace Conference (1925). There also were extensive memoirs and volumes of published documents that provided much material for diplomatic historians and other international relations scholars.

The newly created League of Nations, which ushered in the hope and expectation that a new and peaceful world order was at hand, was a second subject that captured significant attention. Some of the international relations schools that were founded in the interwar period were explicitly created to prepare civil servants for what was expected to be the dawning age of international government. Accordingly, intensive study was devoted to the genesis and organization of the league, the history of earlier plans for international federations, and the analysis of the problems and procedures of international organization and international law.

The third focal point of international relations scholarship during the early part of the interwar period was an offshoot of the peace movement and was concerned primarily with understanding the causes and costs of war, as well as its political, sociological, economic, and psychological dimensions. Interest in the question “Why war?” also brought a host of social scientists, including economists, sociologists, psychologists, and even mathematicians—all of whom were pioneers in the intellectual movement known as behaviourism—into active participation in international studies for the first time.

In the 1930s the breakdown of the League of Nations, the rise of aggressive dictatorships in Italy, Germany, and Japan, and the onset of World War II produced a strong reaction against international government and against peace-inspired topics in the study of international relations. The moralidealisminherent in these topics was criticized as unrealistic and impractical, and the academic study of international relations came to be regarded as the handiwork of starry-eyed peace visionaries who ignored the hard facts of international politics. In particular, scholars of international relations were criticized for suggesting standards of international conduct that bore little resemblance to the real behaviour of nations up to that time. As the desired world of peaceful conflict resolution and adherence to international law grew more distant from the existing world of aggressive dictatorships, a new approach to the study of international relations, known as realism, increasingly dominated the field. Nevertheless, the scholarly work on world affairs of the early interwar period, despite the decline in its reputation and influence, was extensive and sound, encompassing the collection and organization of large amounts of important data and the development of some fundamental concepts.

Some topics of study in international relations that are still considered novel or of recent origin were already being vigorously explored in the interwar period. Indeed, a brief review of these topics tends to undermine the image of the interwar period as one dominated by moralistic ideas. The topics include the causes of wars; the relationship between international affairs and the problems of racial and ethnic minorities; the effects of population change on foreign policies; the effects of nationalism, imperialism, and colonialism; the strategic aspects of international relations, including the importance of geographic location and spatial relationships (geopolitics) for military power and the influence on governments of what later was called the “military-industrial complex”; the implications of economic inequalities between countries; and the role of public opinion, national differences, and cultural orientation in world affairs. Although these earlier studies tended to be somewhat short on theory and long on description, most of the topics examined remain relevant in the 21st century.

The scholarly contributions of some individuals in the 1930s were particularly noteworthy because they foreshadowed the development of international relations studies after World War II. Harold D. Lasswell, for example, explored the relationships between world politics and the psychological realm of symbols, perceptions, and images; Abram Kardiner and his associates laid the groundwork for an approach, based on a branch of anthropology known as culture-and-personality studies, that later became a popular but short-lived theory of international relations; Frederick L. Schuman, setting a style that is still followed by interpreters of foreign policy and by journalists, synthesized analytic commentary with accounts of current international events; Quincy Wright investigated numerous aspects of international behaviour and war as head of one of the first team research projects in international relations; and E.H. Carr, Brooks Emeny, Carl J. Friedrich, Schuman, Harold Sprout, Nicholas Spykman, and others developed the main lines of what became the “power-politics” explanation of international relations, also known as realism. In 1937 the Spanish poet, historian, philosopher, and diplomat Salvador de Madariaga, founder of the College of Europe, relied upon his experience in working with the League of Nations Secretariat in Geneva to describe the gap between what was being said or written about international relations and what was actually happening.

The broadened definition and scope of the study of international relations were among the fundamental contributions of scholars of the interwar period. Many of these innovators were enlisted by governments during World War II for work in intelligence and propaganda, as well as other aspects of wartime planning. In this respect the war stimulated systematic social-scientific investigations of international phenomena. It also led to important technological advances—notably the computer—that would later have a major impact on the study of international relations.

In other ways World War II was a divide for academic international relations. The war itself brought about a drastic change in the agenda of world politics, and the postwar intellectual climate was characterized by a marked shift away from many earlier interests, emphases, and problems. In the early postwar years there was a quest for analyses that would cut through the details of studies of myriad international topics to produce a general understanding of common elements and a clear view of the fundamental nature of international politics. There was also a growing interest in developing theories that could help to explain the major issues of the changing international scene. New security issues emerged, including the issue of nuclear weapons, which led to extensive writings on deterrence as a basis of strategic stability. Bernard Brodie’streatise on nuclear deterrence was highly influential, as was the work of Herman Kahn, Glenn Snyder, Thomas C. Schelling, Henry A. Kissinger, and Albert Wohlstetter. Other issues that were addressed in the vast literature of international relations include international, and especially European, integration; alliances and alignment, such as the North Atlantic Treaty Organization (NATO); ideologies; foreign-policy decision making; theories about conflict and war; the study of low-intensity conflict; crisis management; international organizations; and the foreign policies of the increasing number of states that became part of the international system in the mid- to late 20th century.

Hans J. Morgenthau’s Politics Among Nations (1948) helped to meet the need for a general theoretical framework. Not only did it become one of the most extensively used textbooks in the United States and Britain—it continued to be republished over the next half century—it also was an essential exposition of the realist theory of international relations. Numerous other contributors to realist theory emerged in the decade or so after World War II, including Arnold Wolfers, George F. Kennan, Robert Strausz-Hupé, Kissinger, and the theologian Reinhold Niebuhr.

Although there are many variations of realism, all of them make use of the core concepts of national interest and the struggle for power. According to realism, states exist within an anarchic international system in which they are ultimately dependent on their own capabilities, or power, to further their national interests. The most important national interest is the survival of the state, including its people, political system, and territorial integrity. Other major interests for realists include preservation of the culture and the economy. Realists contend that, as long as the world is divided into nation-states in an anarchic setting, national interest will remain the essence of international politics. The struggle for power is part of human nature and takes essentially two forms: collaboration and competition. Collaboration occurs when parties find that their interests coincide (e.g., when they form alliances or coalitions designed to maximize their collective power, usually against an adversary). Rivalry, competition, and conflict result from the clash of national interests that is characteristic of the anarchic system. Accommodation between states is possible through skillful political leadership, which includes the prioritizing of national goals in order to limit conflicts with other states.

In an international system composed of sovereign states, the survival of both the states and the system depends on the intelligent pursuit of national interests and the accurate calculation of national power. Realists caution that messianic religious and ideological crusades can obscure core national interests and threaten the survival of individual states and the international system itself. Such crusades included, for Morgenthau, the pursuit of global communism or global democracy, each of which would inevitably clash with the other or with other competing ideologies. The attempt to reform countries toward the ideal of universal trust and cooperation, according to realists, runs counter to human nature, which is inclined toward competition, conflict, and war.

Realist theory emerged in the decade after World War II as a response to idealism, which generally held that policy makers should refrain from immoral or illegal actions in world affairs. As no impressive new formulation of political idealism appeared on the international scene to reply to realist theory, the debate between realism and idealism gradually faded, only to be revived in a somewhat different form in the final decades of the 20th century in the disagreement between neoliberal institutionalists and neorealist structuralists.

Many international relations scholars neither rejected nor embraced realism but instead were engrossed in other aspects of the broadening agenda of international relations studies. Beginning in the 1950s, as the United States became more fully engaged in world affairs, the U.S. government made large sums of money available for the development of area studies, especially studies of regions that were important in the intensifying Cold War with the Soviet Union. In order to understand the major forces and trends shaping countries such as the Soviet Union and China or the regions extending from Africa to Northeast Asia, the United States needed to recruit greater numbers of specialists in the histories, politics, cultures, economies, languages, and literature of such areas; the Soviet Union did likewise. Theoretical concerns generally played a marginal role in the growth of area specialization in the West. Although many scholars agreed with Morgenthau’s statement that theory and research should have a “concern with human nature as it actually is, and with the historic processes as they actually take place,” they did not uniformly believe that realism was capable of providing an adequate explanation of international behaviour.

The behavioral approach and the task of integration

In the 1950s an important development in the social sciences, including the study of international relations, was the arrival of new concepts and methodologies that were loosely identified in ensemble as behavioral theory. This general approach, which emphasized narrowly focused quantitative studies designed to obtain precise results, created a wide-ranging controversy between theorists who believed that the social sciences should emulate as much as possible the methodologies of the physical sciences and those who held that such an approach is fundamentally unsound. In addition, the great number of new topics investigated at the time—including cognition, conflict resolution, decision making, deterrence, development, the environment, game theory, economic and political integration, and systems analysis—provoked some anxiety that the discipline would collapse into complete conceptual and methodological chaos. Accordingly, much of the intellectual effort of the mid-1950s to mid-1960s—the so-called “behavioral decade”—went into the task of comparing, interpreting, and integrating various concepts from new areas of study, and the scholarly goal of the period was to link theories, or to connect so-called “islands of theory,” into a greater, more comprehensive theory of international relations.

This task proved to be a difficult one. Indeed, some scholars began to question the necessity—or even the possibility—of arriving at a single theory that would explain all the varied, diverse, and complex facets of international relations. Instead, these researchers suggested that a number of separate theories would be needed.

At the same time, theories that trace the forces of international relations to a single source were increasingly viewed as unsatisfactory. The struggle for power, for example, was accepted as a fact in past and current international politics, but attempts to make all other factors subordinate to or dependent upon power were thought to exclude too much of what is important and interesting in international relations. Similar assessments were made of the theory that asserts that the character of a nation—and hence the character of its participation in international relations—is determined by its child-rearing practices, as well as of the Marxist theory that international relations are solely the historical expression of class struggle.

The general attitude of the behavioral decade was that the facts of international relations are multidimensional and therefore have multiple causes. This conclusion supported, and in turn was supported by, the related view that an adequate account of these facts could not be provided in a single integrated theory and that multiple separate theories were required instead. By the 1960s, for example, studies of international conflict had come to encompass a number of different perspectives, including the realist theory of the struggle for power between states and the Marxist notion of global class conflict, as well as other explanations. At the same time, conflict theory coexisted with economic and political integration theory and game theory, each of which approached the phenomena of international conflict from a distinct perspective.

In keeping with the multiple-theory approach, by the end of the behavioral decade there was a growing consensus that the study of international relations should encompass both quantitative and qualitative analyses. Whereas quantitative methodologies were recognized as useful for measuring and comparing international phenomena and identifying common features and patterns of behaviour, qualitative analyses, by focusing on one case or a comparison of cases involving specific research questions, hypotheses, or categories, were thought to provide a deeper understanding of what is unique about political leaders, nations, and important international events such as World War II and the Cold War.

The use of quantitative analysis in international relations studies increased significantly in the decades after the 1960s. This was a direct result of advances in computertechnology, both in the collection and retrieval of information and in the analysis of data. When computers were introduced in international relations studies, it was not readily apparent how best to exploit the new technology, partly because most earlier studies of international relations were set forth in narrative or literary form and partly because many of the phenomena examined were not easily quantifiable. Nevertheless, exploratory quantitative studies were undertaken in a number of directions. A growing body of studies, for example, developed correlations between phenomena such as alliances and the outbreak or deterrence of war, between levels of political integration and levels of trade, communication, and mobility of populations, between levels of economic development and internal political stability, and between levels of internal violence and participation in international conflicts.

The later 20th century

Foreign policy and international systems

The influence of behaviourism helped to organize the various theories of international relations and the discipline into essentially two principal parts, or perspectives: the foreign-policy perspective and the international-system-analysis perspective. Within each of these perspectives there developed various theories. The foreign-policy perspective, for example, encompasses theories about the behaviour of individual states or categories of states such as democracies or totalitarian dictatorships, and the international-system-analysis perspective encompasses theories of the interactions between states and how the number of states and their respective capabilities affect their relations with each other. The foreign-policy perspective also includes studies of the traits, structures, or processes within a national society or polity that determine or influence how that society or polity participates in international relations. One such study, known as the decision-making approach, analyzes the information that decision makers use, their perceptions and motivations, the influence on their behaviour of public opinion, the organizational settings in which they operate, and their intellectual, cultural, and societal backgrounds. Studies that analyze the relations between the wealth, power, or technological level of a state and its international status and role provide other illustrations of the foreign-policy perspective.

Comparative foreign-policy analysis first appeared during the mid-1960s. By comparing the domestic sources of external conduct in different countries, using standard criteria of data selection and analysis, this approach seeks to develop generalized accounts of foreign-policy performance, including theories that explore the relationship between the type of domestic-external linkage a country displays and its political and economic system and level of social development. Some research also has explored the extent to which certain patterns of behaviour, such as violent demonstrations or protests, may spread from one state to another.

Whereas foreign-policy analysis concentrates on the units of the international system, international-system analysis is concerned with the structure of the system, the interactions between its units, and the implications for peace and war, or cooperation and conflict, of the existence of different types of states. The term interactions suggests challenge and response, give and take, move and countermove, or inputs and outputs. Diplomatic histories feature narratives of action and response in international situations and attempt to interpret the meanings of the exchanges. Balance-of-power theory, which asserts that states act to protect themselves by forming alliances against powerful states or coalitions of states, is another example of the international-system perspective. Still other examples include explanations and descriptions of bargaining in international negotiations and studies of arms races and other escalating action-reaction processes.

The general-system perspective

The so-called general-system perspective on international relations, which attempts to develop a comprehensive understanding of the dynamics of the relations between states, may be compared to the map of a little-explored continent. Outlines, broad features, and a continental delineation are not in question, but everything else remains in doubt, is subject to controversy, and awaits exploration. The Russian-born mathematician and biologist Anatol Rapoport once remarked that general-system theory is not really a theory but instead “a program or a direction in the contemporary philosophy of science.”

The concept of a system can be used to study patterns of interaction within and between units of foreign-policy decision making; by exploring such patterns, one can determine how foreign policies are formulated and how states or other units interact with or are related to each other , as opposed to how they interact with outside units. The members of a family, for example, interact with each other in ways that clearly differ from the ways in which they interact with other persons, such as colleagues in a place of employment or fellow members of a church. Although systems are definable in terms of units that exhibit certain patterns of interaction with each other, there also may be interaction between a system and its subsystems. A national political system, for example, may interact with subsystems such as interest groups, the media, or public opinion.

Systems and subsystems exist in a hierarchical setting. A department is a subsystem of a corporation, for example, just as a corporation is a subsystem of an industry. In international relations states are considered subsystems, or components, of the entire international system. In analyzing the international system, researchers often posit distinct political, economic, cultural, and social subsystems.

Although interactions between states have varied over time, by the latter decades of the 20th century they had become global in scope and unprecedented in their number and in the types of actors they involved. The volume, velocity, and types of interaction had expanded to include not only the greater movement of people but also trade, investment, ideas, and information—all of which were shaped by technology.

Structures, institutions, and levels of analysis

Since the 1970s the study of international relations has been marked by a renewed debate about the relationship between structures and institutions in international systems. On one side of the controversy was a revival of the school of realism, known as neorealism, which emerged with the publication of Kenneth Waltz’sTheory of International Politics in 1979. Neorealism represented an effort to inject greater precision, or conceptual rigour, into realist theory. While retaining power as a central explanatory notion, Waltz’s neorealism also incorporated the idea of structure as it is reflected in alliances and other cooperative arrangements among states of varying sizes, strengths, and capabilities. A bipolar system, for example, is a structure in which two states are dominant and the remaining states are allied with one or the other dominant state. According to Waltz and other neorealists, the structure of the international system limits the foreign-policy options available to states and influences international institutions in important ways. The United Nations (UN), for example, mirrors the structure of the existing international system insofar as it is dominated by leading powers such as the permanent members of the Security Council. Changes in international structure, including the rise of new powers, eventually lead to changes within international institutions. Thus, some neorealists have suggested that the Security Council’s permanent membership will eventually be expanded to include countries such as Germany, India, Japan, and others.

On the other side of the structures-institutions debate have been the neoliberal institutionalists, who contend that institutions matter beyond simply reflecting or codifying the power structure of the international system. Although neoliberal institutionalists accept the realist conception of states as the principal actors in a fundamentally anarchic environment, they argue that state behaviour can be modified by interaction with international institutions such as the European Union (EU), NATO, the World Trade Organization (WTO), and the UN. Such interaction, they contend, reduces the long-term potential for international conflict.

Although neorealist structuralists and neoliberal institutionalists generally agree that international cooperation is possible, neorealists are much more skeptical of its chances for long-term success. According to neorealist logic, NATO should have dissolved in the 1990s after the collapse of the Soviet Union and the bipolar structure that had led to its formation. Instead, NATO was transformed in the decade following the end of the Cold War, taking on new tasks and responsibilities. This contradiction may be apparent, however, only because such adaptation can be viewed as reinforcing the neorealist thesis that institutions reflect the existing international structure: when that structure changes, they must change accordingly if they are to survive. Thus, NATO was able to survive because it underwent a transformation. At the same time, NATO’s adaptation reflects the neoliberal-institutionalist contention that international organizations can modify national interests through the process of cooperation. Thus, NATO countries have altered their policies to take account of the needs of other members, and potential members have undergone rigorous internal reform in order to qualify for membership. Consequently, each theory appears to offer useful insights, and both together can form the basis of a unified approach to the relationship between structures and institutions.

Central to neorealist structural theory is the levels-of-analysis question—i.e., the question of whether international inquiry should be focused at the individual, state, international-system, or other level. Introduced in the 1950s as part of an attempt to make research in international relations more scientific, the levels-of-analysis question provided a conceptual basis for addressing issues such as the effect of structure (bipolar or multipolar) on the behaviour of states or other units. At the same time, it offered a means of distinguishing between different sources of explanation and different objects of analysis. Thus, assuming that the international system shapes the options available to states as actors, it is plausible to suggest that the way in which decision makers respond to such options depends on how they perceive them and on the related opportunities and constraints created by domestic-level forces. In the 1980s this perspective was reflected in the burgeoning literature on “democratic peace theory,” an approach that President Wilson undoubtedly had in mind when he called on Congress to support an effort “to make the world safe for democracy.” Democratic peace theorists appealed to the internal characteristics of democratic states in order to explain why democracies tend not to fight each other. According to them, the peaceful norms that democratic states have developed for resolving differences with each other are an outgrowth of their domestic traditions of law and order, compromise, due process, protection of individual rights—including property rights and the right to freedom of speech—and an independent judiciary. In The Twenty Years’ Crisis, 1919–1939: An Introduction to the Study of International Relations (1939), E.H. Carr contended that individuals’ interest in the creation of a peaceful world could determine the foreign policies of democracies. A world constituted entirely of democracies, according to this view, would be peaceful.

By the late 1990s neorealist structuralist theory had been supplemented, in what was termed neoclassical realist theory, by explorations of the implications of structure, not just at the international-system level but also at the state level and within the state at the individual and group levels. Realist theory continued to be marked by major disagreements, however, a situation that supporters claimed was a reflection of rich intellectual resources and that detractors cited as an indication of fractured conceptual foundations. In any event, the contemporary effort to update, refine, and broaden realist theory, as well as the ongoing debate between neorealism and neoliberalism, may represent a trend toward a synthesis of the various realist schools of thought.

Recent perspectives

Constructivism

In the late 20th century the study of international relations was increasingly influenced by constructivism. According to this approach, the behaviour of humans is determined by their identity, which itself is shaped by society’s values, history, practices, and institutions. Constructivists hold that all institutions, including the state, are socially constructed, in the sense that they reflect an “intersubjective consensus” of shared beliefs about political practice, acceptable social behaviour, and values. In much the same way, the individual members of the state or other unit continuously construct the reality about which policy decisions, including decisions about war and peace and conflict and cooperation, are made.

Some constructivists contend that gender is socially constructed. On the basis of this thesis, feminist theories of international relations have attempted to address the fundamental question of the extent to which gender-based role differentiation is socially rather than biologically determined. In so doing, they have sought to answer questions such as: Are men more prone than women to aggressive, warlike behaviour? If gender roles are socially constructed, then according to feminist theory it would be possible to reduce male aggressiveness by changing beliefs or values regarding what it is to be male. On the other hand, if aggression is the product of male biology, then such change becomes impossible, or at least considerably more difficult.

Part of the newer intellectual landscape in the study of international relations is formed by postmodernism and critical theory. According to postmodernism, the international structures posited in realist and other international relations theory are social constructions that reflect a worldview that serves the interests of elites. Critical theory was developed from the 1920s by the Frankfurt School of social and political philosophers, especially Jürgen Habermas and Herbert Marcuse (1898–1979). For critical theory the essential issue is how to emancipate human beings from social institutions and practices that oppress them. Although inspired by Marxism, critical theorists recognize forms of domination other than class domination, including those based on gender, race, religion, ethnicity, and nationalism. Because each of these forms has been in abundant evidence in the global landscape, critical theory was thought to provide important insights into the study of international relations at the start of the 21st century.

International political economy

Nothing is more illustrative of the inherently interdisciplinary nature of international relations inquiry than the nexus between economic and political factors. Although politics and economics have been studied separately for analytic purposes and as academic disciplines, and although each has its own paradigms, theories, and methodologies, it has long been recognized that economic factors shape political decisions, just as political factors may have a decisive influence on economic choices. Writings on political economy proliferated from the rise of the modern state in the mid-17th century until the mid-19th century. Much of the literature emphasized mercantilism, the notion that economic activity is, or should be, subservient to the interests of the state. Influenced by the work of Adam Smith (1723–90), David Ricardo (1772–1823), Richard Cobden (1804–65), and John Stuart Mill (1806–73), political economists of this period developed a fundamentally different approach, known as economic liberalism, that held that a system of free trade supported by government policies of laissez-faire would lead to economic growth and expanded trade and make an important contribution to international peace. In the latter 19th century a third approach, based on the writings of Karl Marx, argued that an increasingly poor proletariat and an increasingly affluentbourgeoisie would eventually clash in a violent revolution resulting in the overthrow of the latter, the destruction of capitalism, and the emergence of communism.

Each of these sharply differing approaches has left its imprimatur on contemporary theories of international political economy. The earlier mercantilist approach influenced contemporary economic nationalism, which is characterized by several important assumptions: (1) states cannot remain powerful in an anarchic setting without a strong economy, (2) economic strength must be preserved by protecting key industries and jobs, (3) such protectionism may require tariffs and governmental subsidies, (4) low-priced imports may threaten domestic jobs and industry, (5) the state can and should remain sovereign in economic matters, and (6) membership in international economic organizations such as the WTO and agreements such as the North American Free Trade Agreement may have adverse consequences for national strength.

Contemporary economic liberalism shares with classical liberalism the contention that the only way a state can maximize economic growth is by allowing markets to operate free from government intervention. They maintain that tariffs—which have the effect of distorting the allocation of resources, production, and trade—restrict economic growth and should be abolished. Accordingly, they support the creation and expansion of regional and international free-trade organizations. Citing Ricardo’s theory of comparative advantage and earlier ideas of Smith, they also argue that national specialization is essential to world prosperity because it entails that countries will produce only those goods and services they are best equipped to make, which thus maximizes overall efficiency and minimizes overall costs. More generally, liberals maintain that the basic units of the global economy are now so closely integrated that efforts on the part of states to restrict trade with other countries are bound to fail. Debate between economic nationalists and liberals centres on the extent to which the state, even if it can do so, should halt or reverse the forces leading to economic globalization.

The third basic contemporary approach to international political economy is rooted in Marxism, though the collapse of nearly all states with Marxist economies greatly undermined Marxist-inspired theories of international relations. Focusing on the relationship between wealthy states and impoverished ones, this approach, known as dependency theory, rejects the assumption that capitalism is the best means of economic development for impoverished states and instead argues that participation in international capitalism by poorer countries traps them in relationships of dependency and subordination to wealthier states.